.gitignore: ignore u-boot.elf and tools/relocate-rela

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/tools/.gitignore b/tools/.gitignore
index 930fa2e..cd2f041 100644
--- a/tools/.gitignore
+++ b/tools/.gitignore
@@ -10,6 +10,7 @@
 /mxsboot
 /ncb
 /proftool
+/relocate-rela
 /ubsha1
 /xway-swap-bytes
 /*.exe